Ramesha Reddy - Academia.edu (original) (raw)

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Papers by Ramesha Reddy

Journal of Optoelectronics and Advanced Materials, 2007

The effects of thermal annealing temperature on electrical characteristics of rhodium (Rh) and rh... more The effects of thermal annealing temperature on electrical characteristics of rhodium (Rh) and rhodium/gold (Rh/Au) Schottky contacts to n-type GaN (n d =4.07x10 17 cm -3 ) have been investigated by current-voltage (I-V) and capacitance-voltage (C-V) techniques. Measurements showed the barrier height of as-deposited Rh Schottky contact is 0.60 eV (I-V) and 0.98 eV (C-V) respectively. However, the Schottky barrier height is somewhat decreased upon annealing at 500 °C, reaching values of 0.51 eV (I-V) and 0.65 eV (C-V). The Schottky barrier height of as-deposited Rh/Au is found to be 0.57 eV (I-V) and 0.62 eV (C-V). However, the Schottky barrier height increased with annealing temperature up to 500 °C, reaching maximum values of 0.84 eV (I-V) and 1.05 eV (C-V). Significant improvement in the electrical characteristics in the case of Rh/Au Schottky contact is observed upon annealing temperature compared to the Rh Schottky contact. The Rh Schottky contact is relatively stable during ann...

Microelectronic Engineering, 2006

We have investigated the microstructural and electrical characteristics of Ti/W/Au ohmic contacts... more We have investigated the microstructural and electrical characteristics of Ti/W/Au ohmic contacts on n-type GaN (4.0 • 10 18 cm À3) using Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) after annealing at 900°C. It is shown that the electrical properties are improved upon annealing at 900°C for 1 min in nitrogen ambient. The 900°C annealed contact produced a specific contact resistance of 8.4 • 10 À6 X cm 2. It is further shown that the contact exhibits thermal stability during annealing at 900°C. Based on the Auger electron microscopy and transmission electron microscopy studies, the formation of TiN layer results in an excess of N vacancies near the surface of the GaN layer, which could be the reason for the low-resistance of the Ti/W/Au contact.

Semiconductor Science and Technology, 2006

The effect of thermal annealing temperature on electrical and structural properties of Rh/Au Scho... more The effect of thermal annealing temperature on electrical and structural properties of Rh/Au Schottky contacts to n-type GaN (~4 × 1017 cm-3) has been investigated by current-voltage (I-V), capacitance-voltage (C-V), x-ray diffraction (XRD) and Auger electron microscopy (AES). Calculations showed that the Schottky barrier height of the as-deposited Rh/Au contact was 0.57 eV (I-V) and 0.62 eV (C-V), respectively. However,

Applied Physics A, 2013

Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a... more Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a Cu diffusion barrier layer used in porous low-k dielectrics. This study investigates the effect of annealing temperature on the electrical characteristics and reliability of the dielectric stacks with HfO 2 and porous low-k films. The experimental results reveal that annealing improved electrical performance and reliability, but increased the dielectric constant. However, the resulting dielectric constant of the annealed HfO 2 /porous low-k dielectric stacks following oxygen plasma treatment was still lower than that of the dielectric stacks without annealing, indicating that annealing improved the properties of HfO 2 /porous low-k dielectric stacks. Annealing at 400°C improved electrical characteristics, reliability, and Cu barrier performance more than did annealing at 600°C because at 600°C annealing, the grain boundaries of the crystallized HfO 2 film provide a conduction path and cause the breakage of the porous low-k film. However, the HfO 2 /porous low-k dielectric stacks that were annealed at 600°C exhibited greater resistance against damage by oxygen plasma.

Solid-State Electronics, 2005

$Research paper thumbnail of Temperature dependent electrical properties of the epitaxial junction between Nb: SrTiO $ _ {3} $ and magnetite (Fe $ _ {3} $ O $ _ {4} $)$

The Journal of eukaryotic microbiology

An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunos... more An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunoscreening with sera obtained from mice that were either immunized with an amoebic lysate or infected with trophozoites. The coding nucleotide sequence of the cloned gene consisted of 357 bases that were translated into 119 amino acids. This gene was designated as nfa1. The predicted amino acid sequence of Nfa1 protein has two potential glycosylation and three potential phosphorylation sites, and its predicted secondary structure consists of four helices and three corners. The deduced amino acid sequence of Nfa1 protein shares 43% identity with the myohemerythrin (myoHr) protein from a marine annelid, Nereis diversicolor, including 100% identity in conserved regions and iron-binding residues. A phylogenetic tree constructed from amino acid sequences placed the N. fowleri Nfa1 protein outside of a cluster of myoHr proteins from eight invertebrates. A purified recombinant protein that migrat...